Rotatable latching relay



United States Patent O 3,189,706 RGTATABLE LATCHING RELAY Norman E. Helmstetter, Pine Brook, and Anthony Scala, Livingston, NJ., assignors to Tung-Sol Electric Inc., a corporation of Delaware Filed Apr. 3, 1963, Ser. No. 270,343 6 Claims. (Cl. 264)-87) This invention relates to a latching relay which is secured in either one of two positions. The invention has specific relation to a latching means applied to relay armatures which retains the armature in its operated position regardless of accelerating forces applied to the body of the relay.

The usual relay in its simplest form comprises an electromagnetic coil having a ferromagnetic core and a rockable armature which either carries contacts or operates them. Such an arrangement is obviously subject to operation by accelerating forces which may act on the body of the relay in any number of directions to move the armature and operate the contacts at the wrong time. Latching or locking relays have been designed which include a mechanical latch held by a spring and positioned so that the latch holds the armature in a desired position until the relay is operated by the production of magnetic flux. These relays have been popular, but they are also affected by high accelerating forces which move the latches out of their locked position and permit the armatures to be moved at a time when they should be held motionless.

`The present invention uses a rotatable armature with four mechanical latches disposed in such a manner that they will retain the armature in its desired position regardless ofV applied mechanical forces. Accelerating forces of at least fifty times gravity can be applied to the relay without changing the position of the armature or the position of the electrical contacts.

One ofthe objects of this invention is to provide animproved latching relay which avoids one o1- more of the disadvantages and limitations of prior art relays.

i Another object of the invention is to provide a relay having an armature which can be securely latched into either one of two operative positions.

Another object of the invention is to eliminate the effects of high acceleration forces on the latching components.

- armature is axially mounted adjacent to the pole pieces and is formed with a ferromagnetic portion for rocking the armature when magnetic ilnx is applied to selected pole pieces. The armature is formed with a plurality of slots in its outer surface for engagement by latching devices. The armature is coupled to a rotatable contact maker for opening and closing electrical contacts which can be connected to external circuits. A plurality of mechanical latches are mounted adjacent to the pole pieces and are resiliently stressed to move toward the armature for engaging the slots. Each latch is formed with a ferromagnetic portion for actuation by the magnetic flux in the adjacent pole piece.

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.

FIG. l is a cross sectional view taken along the axis of the relay and shows the armature, the pole pieces, the

3,189,706 Patented June 15, 1965 contact maker, and two latches which engage the armature.

FIG. 2 is a cross sectional view of the relay shown in FIG. l and is taken along line 22 of that figure.

FIG. 3 is another cross sectional view of the relay shown in FIG. 1 and is taken along line 3-3 of that figure.

FIG. 4 is an isometric view of the contact maker.

FIG. 5 is a cross sectional view of an alternate arrangement of a latch, drawn to an enlarged scale.

Referring now to the figures, the relay includes a ferromagnetic cylinder 10 which lsupports most of the relay components. Four pole pieces 11, 12, 13 and 14 are secured to the outer cylinder in spaced arrangement. Each pole piece is surrounded by a winding 15, 16, 17 and 18; these windings being shown diagramatically in FIG. 2. Opposite windings 15-17 and 16-18 are generally connected either in series or parallel relationship, and each of these pairs of windings is connected to terminals for connection to operating sources of electrical power. Terminals 20 and 21, as shown in FIG. 2, are connected to windings 15 and 17 in series while terminals 22 and 23 are connected to windings 16 and 18, also in series.

An armature 24 is mounted on an axial shaft 25 which may be journaled at one end in a bearing 26 secured to a disk 27 mounted in cylinder 10. The other end of shaft 25 may be journaled in a bearing 28 which is secured to a similar disk 30. It should be noted that other methods and means of mounting the armature 24 can be used and electrical contacts and the invention is not limited to the form shown. As indicated in FIGS. 3 and 4, the cylinder 31 carries four conductive inserts 32 and these are employed to open and close contact points secured to flexible leaves 33. Cylinder 31 may be securely mounted on shaft 25 or there may be a resilient coupling intermediate the two shaft ends. Other coupling means may be employed.

The relay shown is primarily designed to withstand exa cessive accelerating forces, up to and including fifty times the acceleration due to gravity. For this reason, the entire operating mechanism is secured to a rotatable shaft and the weights about this shaft are equally distributed so that any acceleration movement operating in a straight line will have no tendency to rotate the shaft or i-ts components. Also, in order to retain the armature and the contact maker in its operated position, a series of four latches 35, 36, 37, and 38 are positioned adjacent to the four pole pieces. Each latch is resiliently stressed by a spring 40 to move toward the shaft 25 and engage -a slot 41 to maintain the armature in its operating position. The latches may be formed in several ways, the preferred type being shown in FIG. 2 where .the cylindrical portion of the latch is inserted into a hole 43 in the center of the pole piece. The outer end of the latch comprises a tip 44 which enters slot 41 and holds the armature in place.

ensayos netic portion 24B. In the positionv shown in FIG. 2, power has been applied to terminals 20 and 21 to send current through windings 15 and 17 to withdraw latches 35 and 37 and to turn the armature 24 to the position shown. When the armature arrives at this position, latches 36 and 38 fall into slots 41 and hold the armature in position. It will be obvious that if any force of acceleration operating in a vertical direction up or down, latches 36 and 38 will not be moved and even though latches 35 and 37 are moved a slight amount, they will not affect the position of the armature. If a horizontal acceleration force acts upon the relay, onek of the latches 36 or 38 may be moved out of its latching position, but

the other latch will be retained in its slotand the armature cannot move.

Now let it be assumed that current is applied to terminals 22 and 23. Magnetic flux is generated by windings 16 and 1S and latches 36 and 38 are moved away from shaft 25 and out of slots 41 because of the attraction of the pole pieces to the ferromagnetic collars 45. The armature is then rotated counterclockwise until latches 35 and 37 fall into the other `set of slots 41 to retain the armature in its new position.

An alternative arrangement of latches is shown in FIG. where each pole piece 46 is formed with a slot 47 and a ferromagnetic spring 48 is secured to the cylinder and positioned so that it can move in the slot 47. A tip 44 is secured to the end of spring 48 to engage one of the slots 41. One of the features of this type of latch resides -in the local magnetic path which includes the pole piece 46, spring 48, and cylinder 10. The short length of this path, compared to the arrangement shown in FIG. 2, insures fast release of the latch when the pole piece is magnetized.

From the above description it will be obvious that the relay described and illustra-ted can be operated by the application of an electric current which both unlatches the armature and moves it to a new position where another set of latches engage the armature and retain it in its new operated position. f

The foregoing disclosure and drawings are merely illustrative of the principlesY of this invention and are not to be interpreted in a limiting sense. The only limitations are to be determined from the scope of the appended claims.

We claim:

1. A latching relay comprising, a plurality of pole pieces having inner surfaces arranged around a central axial position, said lpole pieces surrounded by electrical windings with terminals for connection to an operating source 'of electrical power, a rockable cylindrical armature in axial alignment with the pole pieces, the surface of the armature positioned adjacent to the inner surfaces of the pole pieces, selected portions of the armature made of ferromagnetic material for rocking the armature to either one of two positions when magnetic iiux is applied to selected pole pieces, said armature having a plurality of slots formed in its outer surface, a rotatable contact maker coupled to the armature for opening and closing electrical contacts, and at least one mechanical latch mounted adjacent to a pole piece and resiliently stressed to move toward the armature for engaging either one of tWo slots, said latch formed with a ferromagnetic portion for actuation by the magnetic flux in the adjacent pole pieces.

2. A latching relay comprising, four pole pieces having inner surfaces arranged around a central axial position, said pole pieces surrounded by electrical windings with terminals for connection to an operating source of electrical power, a rockable cylindrical armature in axial alignment with the pole pieces, the surface of the armature positioned adjacent to the inner surfaces of the pole pieces, selected portions ofthe armature made of ferromagnetic material for rocking the armature to either one of two positions when magnetic flux is applied to selected pole pieces, said armature having four slots formed in its outer surface, a rotatable contact maker coupled to the armature for opening and closing electrical contacts, and four mechanical latches each mounted adjacent to a pole piece and resiliently stressed to move toward the armature surface for engaging either one of two slots and for holding the armature in its operated position, said latches each including a ferromagnetic portion which is attracted by the adjacent pole piece when current is flowing in the polepiece winding.

3. A latching relay comprising, a plural-ity of pole pieces having inner surfaces arranged around a central axial position, said pole' pieces each surrounded by electrical windings with terminals for connection to an operating source of electrical power, a rockable cylindrical armature in axial alignment with the pole pieces, the surface of the armaturepositioned adjacent to the inner surface of the pole pieces, selected portionsof the armature made of ferromagnetic material for rocking the armature to either one of two position when magnetic flux is applied to selected pole pieces, said armature having` a plurality of slots formed in its outer surface, a mechanical latch mounted adjacent to each pole pierce and resiliently stressed to move toward the armature for engaging either one of -two slots, said latch including a ferromagnetic portion for actuation by the magnetic ux in the adjacent pole pieces, and a contact operating means coupled `to said armature for operating contacts associated Wi-th an external electric circuit. Y

4. A latching relay as claimed in claim 3 wherein said mechanical latches extend into a hole drilled into the centersof the pole pieces.

- 5. A latching relay as claimed in claim 3 wherein said mechanical latches are each provided with a Adisk-like collar'rof ferromagnetic material which is mounted ex- Y' ternal of the pole piece surface and substantially parallel therewith.

6. A latching relay as claimed in claim 3 wherein said latches are secured at one end to a common ferromagnetic cylinder which holds the pole pieces, said latches extending into a slot formed in the adjacent pole pieces, said latch extensions being flexible and resiliently urged to move their free ends toward the armature surface.

References Cited by the Examiner' UNITED STATES PATENTS 2,531,905 11/50 Carpenter 317-197 2,752,513 6/56 Boyd 31o-49 3,035,138 5/62 Scarpa 200-87 3,097,278 7/63 Aiderman 20o-105 3,114,862 12/63 Rice 20o- 93 i FOREIGN PATENTS `596,158 4/60 Canada.

i ROBERT K.' SCHAEFER, Primary Examiner. 

1. A LATCHING RELAY COMPRISING, A PLURALITY OF POLE PIECES HAVING INNER SURFACES ARRANGED AROUND A CENTRAL AXIAL POSITION, SAID POLE PIECES SURROUNDED BY ELECTRICAL WINDINGS WITH TERMINALS FOR CONNECTION TO AN OPERATING SOURCE OF ELECTRICAL POWER, A ROCKABLE CYLINDRICAL ARMATURE IN AXIAL ALIGNMENT WITH THE POLE PIECES, THE SURFACE OF THE ARMATURE POSITIONED ADJACENT TO THE INNER SURFACES OF THE POLE PIECES, SELECTED PORTIONS OF THE ARMATURE MADE OF FERROMAGNETIC MATERIAL FOR ROCKING THE ARMATURE TO EITHER ONE OF TWO POSITIONS WHEN MAGNETIC FLUX IS APPLIED TO SELECTED POLE PIECES, SAID ARMATURE HAVING A PLURALITY OF SLOTS FORMED IN ITS OUTER SURFACE, A ROTATABLE CONTACT MAKER COUPLED TO THE ARMATURE FOR OPENING AND CLOSING ELECTRICAL CONTACTS, AND AT LEAST ONE MECHANICAL LATCH MOUNTED ADJACENT TO A POLE PIECE AND RESILIENTLY STRESSED TO MOVE TOWARD THE ARMATURE FOR ENGAGING EITHER ONE OF TWO SLOTS, SAID LATCH FORMED WITH A FERROMAGNETIC PORTION FOR ACTUATION BY THE MAGNETIC FLUX IN THE ADJACENT POLE PIECES. 